1. Field of the Invention
The present invention relates to an image forming apparatus, and more specifically relates to an image forming apparatus with a sheet processing unit for processing sheets discharged from the main unit of the image forming apparatus, said sheet processing including binding the discharged sheets with a stapler, punching holes in the discharged sheets and the like.
2. Description of the Related Art
Heretofore in the field of copying apparatus, various types of sheet processing units have been provided for accomplishing the processing, e.g., staple process, punch process, stamp process, paste process and the like, of copied sheets disposed in a processing tray in accordance with automated sheet handling in a diversity of ways.
For example, Japanese Patent Application No. 1-193757 discloses a copying apparatus which counts originals being fed onto a glass platen via an automatic document handler, and stops the progress of the copy process when the number of originals exceeds the processing capability of the staple process or punch process, and generates an alarm.
The maximum number of processable sheets M of the stapler in the stapling process and the maximum number of processable sheets N in the punching process generally are different. This dissimilarity in the maximum number of processable sheets is not considered in the previously mentioned apparatus, wherein the maximum number of processable sheets is set at thirty sheets.